Most of us tend to be page-centric when working in WordPress.
If we’re working on Page A, we upload a file right there. But a month later, we work on page D, and upload the same file – again. We wind up with two copies on the server.
Another complicating factor is that you would think to link to a file, you click the link button on the Toolbar. Unfortunately, that’s not how the software works; you have to click the Upload/Insert button, choose the file from the Media library, then click a different button that you’re used to (see this handout for details).
You can use the Media Library to see what photos and files you and your other lab members have already uploaded. This helps you stay within your website’s disk quota.
You can access the Media Library from the WordPress Dashboard menu by clicking Media.